It is difficult to get less costly that one dollar per person per year. http://www.healthwisdom.org/aidsminera.htm Just google how necessary trace minerals are in pig feed. Many drugs planned to be given to humans are tested on pigs because we are more similar than we would wish to admit. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982009001300019